My mother's gas stove LFGF3019NSA has a power burner on the front right side. Mother says it doesn't seem to be as hot as it used to be and she lit it to show me and I agree the flame does not flare out as wide as it used to. What would cause this? I looked down into the center hole and it's totally clean, all the slots in the burner base are clean, and the cap is on it correctly.